Research Paper

Satellite tracking for Mary Lee and Joanna began on June 26, 2002.  Both turtles began their migration on the east coast in Savannah, Georgia where they were released by NOAA sponsored Grey’s Reef National Marine Sanctuary, and moved in a northern direction.  The beginning latitude and longitude for Joanna was 32.000 N and 80.928 W.  The beginning latitude and longitude for Mary Lee was 31.981 N and 81.022 W.  Both turtles followed the same path for most of the way.  Mary Lee took a detour South towards Brunswick, Georgia before heading north again.  The data used to determine the migration patterns of the turtles are the differences in sea surface temperature.  Since data was collected over a time period of three months, the mean temperature was taken of each month to compare the data.  The mean temperature for July was 28.7743 degrees Celsius for Mary lee and 26.6137 for Joanna.  The mean temperature for August was 26.3031 degrees Celsius for Mary Lee and 25.8085 for Joanna.  The mean temperature for September was 23.6943 degrees Celsius for Mary Lee and 23.9016 for Joanna. The CERSER program at Elizabeth City State University began tracking satellite data on July 11, 2002.  That was sixteen days after the tracking of Joanna and Mary Lee began, so data collection began on July 19, 2002, which was the first day that data from CERSER corresponded to the data from WhaleNet.  The comparison for the two turtles ended on September 19, 2002.  This was the last recorded data that the turtles had in common.  The following graph reflects the data collected in the CERSER lab.

Mary Lee (Figure 4) was tracked up until September 20, 2002 which only showed her migration north. 

Joanna was tracked until February 4, 2003 which showed both her migration north and then south.  Joanna’s ending latitude and longitude was 34.008 N and 76.606 W. 

Sea surface temperature data from Physical Oceanographic DAAC was used to validate our sea surface temperature findings. 

The turtles remained close to the shoreline throughout their migration.  For that reason, loggerhead turtles carve to feed in coastal bays and estuaries; in addition to, shallow water along the continental shelves.  Both turtles were spotted on land near the end of August.  Loggerhead turtles nest during the months of May through August.  Most females nest at least twice during the mating season; some may nest up to ten times in a season.  So although there is no proof that the turtles were nesting, it is reasonable to believe that is what they were doing.